The last time I heard from Rafa, it was an email threatening to sue me

Leeds boss Neil Warnock

The outspoken Leeds boss stirred up bad blood between the pair as they prepare to lock horns for the first time since their fall-out.

Benitez leads Chelsea in a Capital One Cup quarterfinal at Elland Road tomorrow night with the interim Stamford Bridge chief set for a frosty reception – and not just from Blues fans.

For the Leeds manager says relations are so bad between the pair that the last time they spoke it was in the form of a solicitor’s note from Benitez threatening legal action.

Warnock blames the Spaniard for helping seal United’s relegation from the Premier League in May, 2007.

The ex-Blades boss said he will never forgive the way his rival’s under-strength Liverpool side slid to a shock late-season defeat at Fulham.

That saved the Craven Cottage side and played a major role in condemning the Yorkshire club to the drop.

Sir Alex Ferguson rang Warnock to say sorry after a weakened Manchester United lost to West Ham on the final day of the campaign to seal his fate – but he is still awaiting an apology from the former Anfield boss.

He has since heard from the 52-year-old but not in the way he expected.

Warnock said: “Enough water has passed under the and I don’t think I should get into that subject.

“The last time I heard from Rafa, it was an email threatening to sue me if I mentioned it again. It had his name on.

“It was his solicitor who was threatening legal action and I’ve still got it in a scrapbook.

“I don’t want to give you any more ammunition than you’ve already got. It’s one of those things that disappoints you in life. You have to get on with it.

“I’ve made my feelings clear over the last few years and nothing will change that.”

Asked if he would break the ice by offering a handshake to his opposite number ahead of the sell-out last-eight clash, he added: “I’ve no idea. I haven’t thought about it yet.”

Warnock insists he has no regrets at turning down the Chelsea manager’s job in 1991 – even though he would jump at the chance now.

He isn’t surprised Benitez took the offer to return to the Premier League on a short-term contract and said: “I don’t regret it because you make decisions at the time and they shape your life.

“I wish I could have Chelsea now, yes. I should have got it this time after Roberto Di Matteo left. Roman Abramovich hasn’t had an Englishman in the job yet, has he?

“I wasn’t surprised to see Rafa go there. He’d been out of football for a while, and I’d have rung the chairman up and asked him to give me a chance like a shot if it was me.

“I once did that at Oldham and said, ‘Take me to the end of the season and see how I do’.

“You’ve got to do that to get a job nowadays and it’s a great job to have at Chelsea, interim manager or whatever. He has some fantastic players there.”

Warnock hopes Leeds can take inspiration from the way Yorkshire rivals Bradford shocked Arsenal at the same stage of the competition last week.

“Whatever team I select we can just go out and enjoy it.” he added.

“I hope we give them a good game, but if we play well and they do as well, there’s only one winner. We have to hope they’re not right up to it and that we’re on top of our game.”